Automatic lithium supplementing device and high-capacity battery

Abstract

The utility model discloses an automatic lithium supplementing device and a high-capacity battery. The automatic lithium supplementing device comprises a lithium source, a lithium supplementing lead, a resistor and an inductive switch, the lithium source is arranged in a battery inner cavity; one end of the lithium supplementing wire is electrically connected with the lithium source, the other end of the lithium supplementing wire is connected with a battery negative terminal, and an inductive switch and a resistor are sequentially arranged between the connecting end of the lithium supplementing wire and the battery negative terminal and the connecting end of the lithium supplementing wire and the lithium source; and the inductive switch is used for detecting a discharge electric signal of the battery, so that the lithium supplementing lead is switched on or switched off. The lithium supplement device can realize automatic lithium supplement in the battery operation process, and compared with manual operation and control of lithium supplement, the lithium supplement efficiency is high. And secondly, lithium supplement of the battery in the discharge stage is controlled through the inductive switch, and compared with existing continuous lithium supplement, the service life of a lithium source is longer, so that the cycle life of the battery is prolonged. And thirdly, the utilization rate of the lithium source is high, the lithium precipitation phenomenon caused by long-term lithium supplement is effectively avoided, and the cycle life of the battery is further prolonged.

Description

Technical Field

[0001] The utility model belongs to the field of batteries, in particular to an automatic lithium replenishing device and a large-capacity battery. Background Art

[0002] Lithium-ion batteries mainly rely on the movement of lithium ions between the positive and negative electrodes to work. During the charge and discharge process, Li+ is intercalated and deintercalated back and forth between the two electrodes: during charging, Li+ is deintercalated from the positive electrode and intercalated into the negative electrode through the electrolyte, and the negative electrode is in a lithium-rich state; during discharge, the opposite is true.

[0003] During the charge and discharge cycle of lithium-ion batteries, lithium ions are consumed, causing the capacity of the lithium-ion batteries to gradually decay during the cycle, thereby reducing the charge and discharge cycle life of the lithium-ion batteries. Utility Model Content

[0004] In order to overcome the problem that the existing lithium-ion batteries consume lithium ions during the charge and discharge cycle, resulting in the battery charge and discharge cycle life being affected, the first aspect of the utility model provides an automatic lithium replenishing device.

[0005] The automatic lithium replenishing device comprises a lithium source, a lithium replenishing wire, a resistor and an induction switch;

[0006] The lithium source is used to be arranged in the inner cavity of the battery; one end of the lithium replenishing wire is electrically connected to the lithium source, and the other end is used to be connected to the negative terminal of the battery, and the lithium replenishing wire is provided with an inductive switch and a resistor in sequence from the connection end connected to the negative terminal of the battery to the connection end connected to the lithium source; the inductive switch is used to detect the discharge electrical signal of the battery, and then make the lithium replenishing wire conductive or disconnected.

[0007] The lithium replenishment device can realize automatic lithium replenishment during the operation of the battery, and has a high lithium replenishment efficiency compared to manual operation control lithium replenishment. In addition, the lithium replenishment of the battery during the discharge phase is controlled by the induction switch. Compared with the existing continuous lithium replenishment, the service life of the lithium source is longer, thereby improving the cycle life of the battery. Thirdly, the automatic lithium replenishment device has a high lithium source utilization rate, which effectively avoids the lithium precipitation phenomenon caused by long-term lithium replenishment, thereby further improving the battery cycle life.

[0008] Furthermore, the above-mentioned sensing switch is a current sensing switch for detecting the direction of the current in the connecting cable between the battery and the external load.

[0009] Furthermore, in order to better control the lithium replenishment current and improve the lithium replenishment effect, the above-mentioned resistor is a sliding rheostat.

[0010] Furthermore, the lithium source includes two copper mesh layers and a metal lithium layer arranged between the two copper mesh layers.

[0011] Furthermore, the automatic lithium replenishment device further comprises a lithium replenishment power supply, which is used to apply a voltage between the lithium source and the negative electrode during the battery discharge phase so that the lithium replenishment current remains unchanged.

[0012] The second aspect of the utility model also provides a large-capacity battery using the automatic lithium replenishing device. The large-capacity battery has the following three forms:

[0013] First form:

[0014] The large-capacity battery includes an automatic lithium replenishing device, a hollow tube and a plurality of single cells;

[0015] Multiple single cells are placed side by side, and the positive terminals of all the single cells are connected as a total positive electrode, and the negative terminals of all the single cells are connected as a total negative electrode;

[0016] The hollow pipe connects the electrolyte areas in the inner cavities of the individual cells, so that the individual cells are in a unified electrolyte system;

[0017] The lithium source of the automatic lithium replenishing device is placed in the hollow tube;

[0018] One end of the lithium replenishing wire extends into the hollow tube and is connected to the lithium source, and the other end of the lithium replenishing wire extends out of the hollow tube and is connected to the total negative electrode. In addition, an induction switch and a resistor are sequentially arranged on the lithium replenishing wire located outside the hollow tube from the total negative electrode to the lithium source. The induction switch is used to detect the discharge electrical signal of the large-capacity battery, and then the lithium replenishing wire is turned on or off.

[0019] Second form:

[0020] The large-capacity battery includes an automatic lithium replenishing device, a box body and a plurality of single cells;

[0021] Multiple single cells are arranged in the box in the same direction;

[0022] An electrolyte sharing channel is provided in the box body, and the electrolyte sharing channel connects the electrolyte areas of the inner cavities of all the single cells;

[0023] The top plate of the box body is provided with avoidance holes corresponding to the polarity terminals of each single battery; the polarity terminals of each single battery extend out of the avoidance holes, and the top plate area of ​​the outer shell corresponding to the avoidance holes is fixedly sealed with the shell of the single battery;

[0024] The positive terminals of all the cells are connected as the total positive electrode, and the negative terminals of all the cells are connected as the total negative electrode;

[0025] The lithium source of the automatic lithium replenishing device is placed in the electrolyte shared channel;

[0026] One end of the lithium replenishment wire extends into the box and is connected to the lithium source, and the other end of the lithium replenishment wire extends out of the box and is connected to the total negative electrode. In addition, an induction switch and a resistor are sequentially arranged on the lithium replenishment wire located outside the box from the total negative electrode to the lithium source. The induction switch is used to detect the discharge electrical signal of the large-capacity battery, and then the lithium replenishment wire is turned on or off.

[0027] The third form:

[0028] The large-capacity battery includes an automatic lithium replenishing device, an outer box, and multiple bare cells;

[0029] The outer box includes a shell with one end open and an upper cover; the upper cover is provided with poles corresponding to the bare battery cell tabs;

[0030] Multiple bare cells are arranged side by side in the shell, the upper cover is sealed and fixed to the open end of the shell, and the pole lugs of each bare cell are connected to the corresponding poles;

[0031] All the poles connected to the positive poles of the bare battery cells are connected as the total positive pole, and all the poles connected to the negative poles of the bare battery cells are connected as the total negative pole;

[0032] The lithium source of the automatic lithium replenishing device is placed in the electrolyte shared channel;

[0033] One end of the lithium replenishment wire extends into the outer box and is connected to the lithium source, and the other end of the lithium replenishment wire extends out of the outer box and is connected to the total negative electrode. In addition, an induction switch and a resistor are sequentially arranged on the lithium replenishment wire located outside the outer box from the total negative electrode to the lithium source. The induction switch is used to detect the discharge electrical signal of the large-capacity battery, and then the lithium replenishment wire is turned on or off.

[0034] The beneficial effects of the new invention are:

[0035] 1. The lithium replenishment device of the utility model can realize automatic lithium replenishment during the operation of the battery. Compared with the lithium replenishment controlled by manual operation, the lithium replenishment efficiency is high. In addition, the lithium replenishment is controlled only during the discharge stage of the battery through the sensor. Compared with the existing continuous lithium replenishment, the service life of the lithium source is longer, thereby improving the cycle life of the battery. Third, the automatic lithium replenishment device has a high lithium source utilization rate, which effectively avoids the lithium precipitation phenomenon caused by long-term lithium replenishment, thereby further improving the battery cycle life.

[0036] 2. The large-capacity battery of the utility model not only enables each single cell or each bare cell to be in the same electrolyte system by sharing the electrolyte, thereby improving the uniformity of each single cell or each bare cell and improving the cycle life of the large-capacity battery, but also adopts an automatic lithium replenishing device to realize lithium replenishment during the discharge stage of the large-capacity battery, providing a way to repair the large-capacity battery online, which can further improve the cycle life of the large-capacity battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 The principle of the automatic lithium replenishment device of Example 1 applied to a square lithium-ion single cell battery Figure 1 ;

[0038] Figure 2 The principle of the automatic lithium replenishment device of Example 1 applied to a square lithium-ion single cell battery Figure 2 ;

[0039] Figure 3 The principle of the automatic lithium replenishment device of Example 2 applied to a square lithium-ion single cell battery Figure 1 ;

[0040] Figure 4 The principle of the automatic lithium replenishment device of Example 2 applied to a square lithium-ion single cell battery Figure 2 ;

[0041] Figure 5 The capacity change trend diagram of the comparison sample, the charging lithium replenishment sample and the discharging lithium replenishment sample after 400 cycles;

[0042] Figure 6 The capacity retention rate variation trend diagram of the comparison sample, the charging lithium replenishment sample and the discharging lithium replenishment sample after 400 cycles;

[0043] Figure 7 This is a schematic diagram of the structure of a large-capacity battery in Example 3;

[0044] Figure 8 This is a schematic diagram of the structure of a large-capacity battery in Example 4;

[0045] Fig. 9 This is a schematic diagram of the structure of a large-capacity battery in Example 5.

[0046] The accompanying drawings in the figure are marked as follows:

[0047] 1-lithium source, 2-lithium replenishing wire, 3-resistance, 4-inductive switch, 5-square lithium-ion single battery, 6-load, 7-lithium replenishing power source, 8-hollow pipe fittings, 9-single battery, 10-box, 11-electrolyte sharing channel, 12-outer box, 13-bare battery cell, 14-shell, 15-upper cover, 16-pole. DETAILED DESCRIPTION

[0048] In order to make the above-mentioned purposes, features and advantages of the utility model more obvious and easy to understand, the specific implementation methods of the utility model are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the utility model, but not all of them. Based on the embodiments of the utility model, all other embodiments obtained by ordinary persons in the field without creative work should fall within the scope of protection of the utility model.

[0049] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0050] In the description of the present invention, it should be noted that the orientations or positional relationships indicated by the terms "top, bottom" etc. are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0051] During the charge and discharge process of lithium-ion batteries, lithium ions are embedded and released back and forth between the positive electrode and the negative electrode. Due to changes in the structure of the positive and negative electrode active materials, decomposition of the electrolyte, and the formation and destruction of the solid electrolyte (SEI) film on the surface of the negative electrode active material, lithium ions are inevitably consumed, resulting in the continuous decay of the lithium-ion battery capacity and difficulty in having a longer cycle life.

[0052] In order to overcome such problems, the prior art generally adopts the optimization of positive or negative electrode materials to increase the active lithium in lithium-ion batteries, but such solutions require adjustment of the preparation process of the positive and negative electrodes, which makes the production cost of the entire battery higher. There are also solutions in the prior art that use metallic lithium as the third electrode for lithium supplementation. However, the chemical properties of metallic lithium are very active and easily react with moisture in the air. Therefore, the requirements for the environment (air humidity, oxygen content, etc.) and equipment during the supplementation process are relatively high, which increases the difficulty of the process. At the same time, lithium powder is easy to float in the air, resulting in a high safety risk during the supplementation process. In addition, direct lithium supplementation based on metallic lithium is prone to problems such as excessive supplementation leading to negative electrode interface analysis and even short circuit in the battery.

[0053] The utility model arranges a lithium source in the battery and controls the lithium source to generate current between the lithium source and the negative electrode of the battery only to replenish lithium during the discharge process of the battery, and does not replenish lithium for the battery during the discharge and storage process of the battery. After the lithium replenishing device is installed, no additional manual operation is required, and automatic lithium replenishment during the discharge process can be achieved.

[0054] The shape of the lithium source can be set as needed. Usually, its shape should be compatible with the shape of the corresponding installation space in the lithium-ion battery. Generally, a sheet (also referred to as a plate) or a column (also referred to as a strip or a band) is selected. The lithium source includes a lithium metal layer and a metal carrier located between the lithium metal layer and the shell and used to support the lithium metal layer. The material of the metal carrier is not specifically limited. As an example, the material of the metal carrier can be selected from copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, silver alloy or stainless steel. Optionally, the material of the metal carrier is selected from copper, copper alloy or stainless steel. The shape of the metal carrier is not specifically limited and can be selected according to actual needs. The lithium metal layer can be arranged on the surface of the metal carrier by rolling.

[0055] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0056] Example 1

[0057] like Figure 1 and Figure 2 As shown, this embodiment provides an automatic lithium replenishment device, which includes a lithium source 1, a lithium replenishment wire 2, a resistor 3 and an induction switch 4. In this embodiment, the automatic lithium replenishment device is applied to a square lithium-ion single cell 5;

[0058] The lithium source 1 is used to be arranged in the inner cavity of the square lithium-ion single battery 5. The lithium source 1 can be fixed on one side of the electrode assembly of the square lithium-ion single battery 5 by vertical placement (that is, the lithium source is parallel to the side wall of the square lithium-ion single battery shell), or can be fixed between the electrode assembly of the square lithium-ion single battery 5 and the bottom of the square lithium-ion single battery 5 shell by horizontal placement. It should be noted that the lithium source 1 needs to be immersed in the electrolyte;

[0059] Specifically, the lithium source 1 in this embodiment includes two copper mesh layers and a metal lithium layer disposed between the two copper mesh layers. In some other embodiments, the lithium source is a layer of copper foil and a metal lithium layer disposed on the copper foil; however, compared with the structure of two copper mesh layers sandwiching a metal lithium layer in this embodiment, the lithium source structure in this embodiment has a higher stability of the lithium layer.

[0060] One end of the lithium replenishing wire 2 extends into the square lithium-ion single battery 5 and is electrically connected to the lithium source 1, and the other end extends out of the square lithium-ion single battery 5 and is connected to the negative electrode of the square lithium-ion single battery 5, and the portion of the lithium replenishing wire located outside the square lithium-ion single battery 5 is provided with an induction switch 4 and a resistor 3 in sequence from the negative electrode to the lithium source 1;

[0061] The induction switch 4 is used to detect the discharge electrical signal of the square lithium-ion single battery 5, and then trigger the normally open switch to close, and then make the lithium replenishing wire 2 conductive or disconnected.

[0062] Specifically, in this embodiment, the sensing switch 4 is a current sensing switch, which is used to detect the current direction of the cable connecting the square lithium-ion battery 5 and the external load 6. Figure 1 and Figure 2 As shown, the current sensing switch can be used to detect the current direction on the connecting cable between the negative electrode of the square lithium-ion single battery 5 and the external load 6 ( Figure 1 The arrow in the middle indicates the current direction during discharge, and the current sensing switch is closed). It can also be used to detect the current direction on the cable connecting the positive electrode of a square lithium-ion battery and an external load ( Figure 2 The direction of the arrow in the middle is the current direction during discharge, and the current sensing switch is closed).

[0063] Specifically, the resistance value of the resistor 3 can be adjusted according to the size of the lithium replenishment current. A resistor 3 with a suitable resistance value can be selected and installed on the lithium replenishment wire 2 according to the needs, or a sliding rheostat can be directly selected. For the convenience of adjustment, this embodiment preferably uses a sliding rheostat as the resistor.

[0064] Example 2

[0065] After the square lithium-ion single battery is used for a long time, the internal resistance of the lithium source 1 and the battery gradually increases, and the lithium replenishment current generated by the potential difference between the negative electrode and the lithium source 1 will gradually decrease, which will lead to a poor lithium replenishment effect. Therefore, this embodiment adds a lithium replenishment power source 7 on the basis of embodiment 1. Figure 3 and Figure 4 As shown, the lithium replenishment power source 7 is arranged on the lithium replenishment wire 2 and is located between the current sensing switch and the resistor 3. During the lithium replenishment process, the lithium replenishment power source 7 can provide a voltage between the negative electrode and the lithium source 1, so that the lithium replenishment current can always remain unchanged.

[0066] In order to verify the lithium replenishment effect of the automatic lithium replenishment device, this embodiment took three 24Ah square shell lithium iron phosphate batteries produced by the same manufacturer and the same batch, and conducted the following experiments:

[0067] Among them, a 24Ah square-shell lithium iron phosphate battery was used as a control sample (the initial capacity of the battery was 23.01Ah), and the other two 24Ah square-shell lithium iron phosphate batteries were transformed into square lithium-ion single cells with automatic lithium replenishment devices, which were used as discharge lithium replenishment samples (the initial capacity of the battery was 22.46Ah) and charge lithium replenishment samples (the initial capacity of the battery was 23.36Ah).

[0068] The specific transformation process of the discharge lithium replenishment sample and the charge lithium replenishment sample is as follows: open the bottom of the shell of the 24Ah square shell lithium iron phosphate battery in the glove box, place a lithium source at the bottom (the mass of the lithium metal layer is 2-3g), connect one end of the lithium replenishment wire to the lithium source, and lead out the other end to connect to the negative electrode of the 24Ah square shell lithium iron phosphate battery, and then seal the battery shell.

[0069] Use the charging and discharging instrument as the load connected to the battery;

[0070] For the comparison sample, only the 24Ah square-shell lithium iron phosphate battery was connected to the charging and discharging instrument to perform normal charging and discharging.

[0071] The test process of the discharge lithium replenishment sample is as follows:

[0072] A current sensing switch is connected to the lithium replenishment cable between the lithium source and the negative electrode of the square lithium-ion single battery to be replenished. The current sensing switch is bound to the connection cable of the charging and discharging instrument to sense the current direction on the connection cable;

[0073] A voltage is applied between the negative electrode of the square lithium-ion single cell to be replenished and the lithium source using a lithium replenishment power supply to control the lithium replenishment current to always be 1 mA.

[0074] The current sensing switch of the discharge lithium replenishment sample senses that the lithium replenishment wire is turned on during discharge and lithium replenishment begins.

[0075] The test process of charging and lithium supplementing samples is as follows:

[0076] ① A current sensing switch is connected to the lithium replenishment cable between the lithium source and the negative electrode of the square lithium-ion single battery to be replenished. The current sensing switch is bound to the connecting cable of the charging and discharging instrument to sense the current direction on the connecting cable;

[0077] ② Apply voltage between the negative electrode of the square lithium-ion single cell to be replenished and the lithium source using a lithium replenishment power supply to control the lithium replenishment current to always be 1mA.

[0078] The current sensing switch of the charging lithium replenishment sample senses that the lithium replenishment wire is turned on during charging and starts lithium replenishment.

[0079] pass Figure 5 As shown, under the same 400 cycles, compared with the control sample, the charged lithium-replenished sample and the discharged lithium-replenished sample, although the initial capacity of the discharged lithium-replenished sample is the lowest, after 400 cycles, the capacity of the discharged lithium-replenished sample is always on an upward trend, while the capacity of the control sample and the charged lithium-replenished sample is always on a downward trend, and the capacity decrease trend of the control sample is more severe than that of the charged lithium-replenished sample.

[0080] pass Figure 6As shown, under the same 400 cycles, compared with the control sample, the charged lithium-replenished sample and the discharged lithium-replenished sample, the slope of the capacity retention rate of the discharged lithium-replenished sample remains basically unchanged, while the slope of the capacity retention rate of the control sample and the charged lithium-replenished sample is always on a downward trend.

[0081] It can be seen that from the perspectives of capacity and capacity retention rate, lithium replenishment during discharge is the most effective.

[0082] Example 3

[0083] This embodiment provides a solution for applying an automatic lithium replenishing device to a first large-capacity battery, such as Figure 7 As shown, the first large-capacity battery includes a hollow tube 8 and a plurality of single cells 9;

[0084] Multiple single cells 9 are placed side by side, and the positive terminals of all single cells 9 are connected as a total positive electrode, and the negative terminals of all single cells 9 are connected as a total negative electrode; specifically, the connection of the positive terminals of all single cells 9 and the connection of the negative terminals of all single cells 9 are connected by copper or aluminum electrical connection plates;

[0085] The hollow pipe 8 connects the electrolyte areas in the inner cavities of each single cell 9 so that each single cell 9 is in a unified electrolyte system; the hollow pipe 8 can be a complete round or rectangular tube; the hollow pipe 8 can also be a sub-pipeline on each single cell 9 formed by extrusion and splicing.

[0086] The lithium source of the automatic lithium replenishing device is placed in the hollow tube 8;

[0087] One end of the lithium replenishing wire extends into the hollow tube and is connected to the lithium source, and the other end of the lithium replenishing wire extends out of the hollow tube and is connected to the total negative electrode. In addition, an induction switch and a resistor are sequentially arranged on the lithium replenishing wire located outside the hollow tube from the total negative electrode to the lithium source. The induction switch is used to detect the discharge electrical signal of the large-capacity battery.

[0088] Example 4

[0089] This embodiment provides a solution for applying an automatic lithium replenishing device to a second large-capacity battery, such as Figure 8 As shown, the second large-capacity battery includes a box body 10 and a plurality of single cells 9; the plurality of single cells 9 are arranged in the box body 10 along the same direction; an electrolyte sharing channel 11 is provided in the box body 10, and the electrolyte sharing channel 11 connects the electrolyte areas of the inner cavities of all the single cells 9;

[0090] The top plate of the box body 10 is provided with avoidance holes corresponding to the polarity terminals of each single battery 9; the polarity terminals of each single battery 9 extend out of the avoidance holes, and the top plate area of ​​the box body 10 corresponding to the avoidance holes is fixedly sealed with the shell of the single battery 9; the fixed sealing method at this place is:

[0091] Usually, the box top plate area around the avoidance hole can be directly welded to the single battery shell to achieve sealing.

[0092] However, when the height dimensions of each single battery are not completely equal, some single battery shells with smaller height dimensions may have problems with cold welding or even be unable to be welded to the top plate of the large-capacity battery box shell, making it difficult to ensure the sealing of the avoidance hole.

[0093] In order to overcome such problems, a weak portion can be provided in the peripheral area of ​​the avoidance hole. During the welding process, the size difference of each single battery in the height direction is compensated by the deformation of the weak portion, so that the box top plate area around the avoidance hole and the single battery shell are sealed and welded. The weak portion can be an annular groove with the center of the avoidance hole as the center point and opened along the peripheral area of ​​the avoidance hole. The weak portion can also be a long strip groove opened in the peripheral area of ​​the avoidance hole.

[0094] The positive terminals of all the cells are connected as the total positive electrode, and the negative terminals of all the cells are connected as the total negative electrode;

[0095] The lithium source of the automatic lithium replenishing device is placed in the electrolyte shared channel;

[0096] One end of the lithium replenishment wire extends into the box and is connected to the lithium source, and the other end of the lithium replenishment wire extends out of the box and is connected to the total negative electrode. An induction switch and a resistor are sequentially arranged on the lithium replenishment wire located outside the box from the total negative electrode to the lithium source. The induction switch is used to detect the discharge electrical signal of the large-capacity battery.

[0097] Example 5

[0098] This embodiment provides a solution for applying an automatic lithium replenishing device to a third type of large-capacity battery, such as Fig. 9 As shown, the third large-capacity battery includes an outer box 12 and a plurality of bare cells 13; the outer box 12 includes a shell 14 with an open end and an upper cover 15; the upper cover 15 is provided with poles 16 corresponding to the pole ears of the bare cells 13; the plurality of bare cells 13 are arranged side by side in the shell 14, the upper cover 15 is sealed and fixed to the open end of the shell 14, and the pole ears of each bare cell 13 are connected to the corresponding poles 16; all poles connected to the positive pole ears of the bare cells 13 are connected as a total positive pole, and all poles connected to the negative pole ears of the bare cells 13 are connected as a total negative pole;

[0099] The lithium source of the automatic lithium replenishment device is placed in the electrolyte shared channel; one end of the lithium replenishment wire extends into the box and is connected to the lithium source, and the other end of the lithium replenishment wire extends out of the box and is connected to the total negative electrode, and an induction switch and a resistor are sequentially arranged on the lithium replenishment wire located outside the box from the total negative electrode to the lithium source, and the induction switch is used to detect the discharge electrical signal of the large-capacity battery.

Claims

1. An automatic lithium replenishing device, characterized in that: It includes a lithium source, a lithium replenishing wire, a resistor and an induction switch; The lithium source is used to be arranged in the inner cavity of the battery; One end of the lithium replenishing wire is electrically connected to the lithium source, and the other end is used to connect to the negative terminal of the battery, and the lithium replenishing wire is provided with an induction switch and a resistor in sequence from the connection end connected to the negative terminal of the battery to the connection end connected to the lithium source; The induction switch is used to detect the discharge electrical signal of the battery, and then make the lithium replenishment wire conductive or disconnected.

2. The automatic lithium replenishing device according to claim 1, characterized in that: The induction switch is a current induction switch used to detect the direction of the current in the connecting cable between the battery and the external load.

3. The automatic lithium replenishing device according to claim 1, characterized in that: The resistor is a sliding rheostat.

4. The automatic lithium replenishing device according to claim 1, characterized in that: The lithium source comprises two copper mesh layers and a metal lithium layer arranged between the two copper mesh layers.

5. The automatic lithium replenishing device according to any one of claims 1 to 4, characterized in that: It also includes a lithium replenishing power supply, which is used to apply a voltage between the lithium source and the negative electrode during the battery discharge phase so that the lithium replenishing current remains unchanged.

6. A large capacity battery, characterized in that: It comprises the automatic lithium replenishing device according to any one of claims 1 to 5, a hollow tube and a plurality of single cells; Multiple single cells are placed side by side, and the positive terminals of all the single cells are connected as a total positive electrode, and the negative terminals of all the single cells are connected as a total negative electrode; The hollow pipe connects the electrolyte areas in the inner cavities of the individual cells, so that the individual cells are in a unified electrolyte system; The lithium source of the automatic lithium replenishing device is placed in the hollow tube; One end of the lithium replenishing wire extends into the hollow tube and is connected to the lithium source, and the other end of the lithium replenishing wire extends out of the hollow tube and is connected to the total negative electrode. In addition, an induction switch and a resistor are sequentially arranged on the lithium replenishing wire located outside the hollow tube from the total negative electrode to the lithium source. The induction switch is used to detect the discharge electrical signal of the large-capacity battery, and then the lithium replenishing wire is turned on or off.

7. A large capacity battery, characterized in that: It comprises the automatic lithium replenishing device according to any one of claims 1 to 5, a box body and a plurality of single cells; Multiple single cells are arranged in the box in the same direction; An electrolyte sharing channel is provided in the box body, and the electrolyte sharing channel connects the electrolyte areas of the inner cavities of all the single cells; The top plate of the box body is provided with avoidance holes corresponding to the polarity terminals of each single battery; the polarity terminals of each single battery extend out of the avoidance holes, and the top plate area of ​​the outer shell corresponding to the avoidance holes is fixedly sealed with the shell of the single battery; The positive terminals of all the cells are connected as the total positive electrode, and the negative terminals of all the cells are connected as the total negative electrode; The lithium source of the automatic lithium replenishing device is placed in the electrolyte shared channel; One end of the lithium replenishment wire extends into the box and is connected to the lithium source, and the other end of the lithium replenishment wire extends out of the box and is connected to the total negative electrode. In addition, an induction switch and a resistor are sequentially arranged on the lithium replenishment wire located outside the box from the total negative electrode to the lithium source. The induction switch is used to detect the discharge electrical signal of the large-capacity battery, and then the lithium replenishment wire is turned on or off.

8. A large capacity battery, characterized in that: It comprises the automatic lithium replenishing device as claimed in any one of claims 1 to 5, an outer box and a plurality of bare batteries; The outer box includes a shell with one end open and an upper cover; the upper cover is provided with poles corresponding to the bare battery cell tabs; Multiple bare cells are arranged side by side in the shell, the upper cover is sealed and fixed to the open end of the shell, and the pole lugs of each bare cell are connected to the corresponding poles; All the poles connected to the positive poles of the bare battery cells are connected as the total positive pole, and all the poles connected to the negative poles of the bare battery cells are connected as the total negative pole; The lithium source of the automatic lithium replenishing device is placed in the electrolyte shared channel; One end of the lithium replenishment wire extends into the outer box and is connected to the lithium source, and the other end of the lithium replenishment wire extends out of the outer box and is connected to the total negative electrode. In addition, an induction switch and a resistor are sequentially arranged on the lithium replenishment wire located outside the outer box from the total negative electrode to the lithium source. The induction switch is used to detect the discharge electrical signal of the large-capacity battery, and then the lithium replenishment wire is turned on or off.

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